This invention generally relates to absorbent articles and, more particularly, to an improved disposable diaper for incontinent adults or babies.
Infants and other incontinent persons wear disposable diapers to receive and contain feces, urine and other fluid discharges from the body. Disposable diapers function both to contain the discharged materials and to isolate these materials from the body of the wearer and from the wearer's surroundings. Modern embodiments of disposable diaper frequently perform these tasks in a manner superior to that of traditional cloth diapers.
Prior art disposable diapers disclose three basic structural elements: a fluid permeable topsheet designed to be placed next to the wearer's skin; a backsheet which forms, in use, the outer surface of the diaper; and an absorbent element interposed between the topsheet and the backsheet.
The topsheet in prior art diapers is permeable to fluids. The backsheet in prior art diapers is a usually liquid impermeable or repellant. Its function is to contain fluids within the absorbent element thereby protecting the wearer's outer garments and other surfaces from soiling by these fluids. Backsheets are commonly formed of a thin sheet of polyethylene, polypropylene or other flexible moisture impeding materials which are substantially water impervious. However, they are not as soft to the touch as traditional cloth diapers. These materials are also more susceptible to cuts or tears than traditional cloth diapers. One method for overcoming the susceptibility to cuts or tears is to make a thicker backsheet. However, the thicker the backsheet is, the noisier and less biodegradable the disposable diaper is.
The absorbent core of prior art diapers is comprised of a mass of hydrophilic fiber material. These fibers are often formed from cellulose. The core is intended to absorb fluids that permeate the topsheet.
In many disposable diapers a liquid impermeable or repellant layer or the backsheet is bonded to the inside ends of the absorbent core to form end-dams to prevent fluids from escaping the diaper at the waistline. The manufacturing process which produces the hourglass or form-fitting shape of modern disposable diapers creates the desired shape after all the elements of the diaper have been assembled. This process generally precludes utilizing the liquid impermeable layer to form side-dams to prevent fluids from escaping the diaper in the leg area. The escape of body discharges in the leg area, however, is minimized by using elastic leg cuffs.
Instead of or in addition to an elastic leg cuff, some prior art disposable diapers have standing leg cuffs to minimize the escape of body discharges in the leg area. Because of the manufacturing process which produces the hourglass or form-fitting shape, the standing leg cuffs are separate units bonded to the topsheet.
Almost all prior art disposable diapers utilize tape fasteners attached at the projections ("ears") formed by the widest portions of the hourglass shaped diaper to allow for securing the diaper about the wearer. Because the tape fasteners are indiscriminate as what they will stick to, they can stick to each other, the topsheet, other diapers or equipment during the manufacturing process resulting in unusable product or down time in the manufacturer's machinery. Similarly, during use, the tapes can stick to areas of the diaper other than those intended and result in an unusable diaper and customer dissatisfaction. In addition, tape fasteners are expensive and non-biodegradable.